RPSC RAS Prelims 2013 Science and Technology Questions with Solutions

Explanation

Electrical generators operate on the principle of electromagnetic induction, where mechanical energy is used to rotate a coil within a magnetic field to induce an electromotive force, thereby producing electrical energy. Electric motors work on the inverse principle, utilizing the interaction between a magnetic field and an electric current to generate torque and physical motion, which converts electrical energy into mechanical energy. These two devices represent the fundamental applications of electromagnetism for the interconversion of mechanical and electrical energy.

Explanation

A modem, short for modulator-demodulator, is a hardware device that enables a computer to transmit data over traditional communication lines, such as telephone or cable systems. Because computers process information in digital format using discrete binary bits, while these transmission mediums carry information as continuous analog waves, a translation process is required. The modem performs modulation by converting the digital signals from the computer into analog signals for outgoing transmission. It simultaneously performs demodulation by converting incoming analog signals back into digital data that the computer can interpret. This bidirectional conversion is essential for connecting digital equipment to analog-based network infrastructures.

Explanation

Celeron, Pentium, and Core are distinct product lines of central processing units (CPUs) developed and manufactured by Intel Corporation. The Pentium brand was launched in 1993 for high-end consumer desktops, followed by the Celeron series in 1998 as a more affordable, entry-level alternative with reduced cache memory. The Core series, introduced in 2006 with sub-brands like Core 2 Duo and later the i3, i5, and i7 series, represents Intel's mainstream and high-performance processor architecture. These components serve as the primary logic circuitry or the brain of the computer, responsible for interpreting and executing most of the commands from the computer's hardware and software.

Explanation

To find when two events with different periodic intervals will coincide again, we calculate the Least Common Multiple (LCM) of their time intervals. The intervals given are 60 seconds and 62 seconds.

The prime factorization of the intervals is: 60 = 2² × 3 × 5 62 = 2 × 31

The LCM is the product of the highest powers of all prime factors involved: LCM(60, 62) = 2² × 3 × 5 × 31 = 1860 seconds

To convert this duration into minutes: Time in minutes = 1860/60 = 31 minutes

Since the devices last sounded together at 10:00 AM, they will next produce sounds together 31 minutes later, which is at 10:31 AM.

Explanation

Wilson Kipsang Kiprotich, the Kenyan long-distance runner, established a new world record at the Berlin Marathon on September 29, 2013. He completed the 42.195-kilometer course in a time of 2 hours, 3 minutes, and 23 seconds. This performance surpassed the previous world record of 2:03:38, which had been set by his compatriot Patrick Makau at the same venue in 2011. Kipsang's achievement cemented Berlin's reputation as one of the fastest marathon courses in the world due to its flat terrain and favorable weather conditions.

Explanation

The Sultan of Johor Cup is an annual international under-21 field hockey tournament held in Johor Bahru, Malaysia, not an under-19 tournament. The third edition held from September 22 to 29, 2013 featured six participating nations: India, Malaysia, Argentina, England, Pakistan, and South Korea, not eight teams. India won the tournament by defeating host nation Malaysia 3-0 in the final played on September 29, 2013, which makes statement 3 correct. Ramandeep Singh of India finished as the top scorer with 11 goals, not 8 as stated in the question. Only statement 3 is factually accurate. Among the available options, option A, which includes statement 3, is the closest to a correct answer.

Explanation

Poplar is a fast-growing deciduous tree belonging to the genus Populus, which serves as a primary source of ligneous raw material for the paper and pulp industry. Ligneous materials are those derived from woody plants containing lignin and cellulose. Poplar wood is highly valued in pulping because it possesses a high cellulose content and relatively low lignin content compared to many other hardwoods, making the chemical separation of fibers more efficient. Its fibers are well-suited for producing high-quality, bright, and opaque paper used in printing and writing. Due to its rapid growth cycle and suitability for plantation forestry, it is a sustainable and preferred woody feedstock for manufacturing paper pulp.

Explanation

GSAT-7, launched in August 2013 and nicknamed Rukmini, is India's first dedicated communication satellite specifically designed for military applications. It serves the Indian Navy by providing a secure, real-time communication platform that links warships, submarines, aircraft, and land-based command systems. The satellite carries payloads in UHF, S-band, C-band, and Ku-band, allowing it to provide comprehensive coverage over the Indian Ocean Region. It is a critical component for network-centric warfare, enabling the seamless exchange of data and voice communication for defense operations.

Explanation

GSAT-7, also known as Rukmini, is India's first dedicated multi-band communication satellite designed specifically for military applications, primarily serving the Indian Navy. Launched in August 2013, the satellite provides real-time, secure communication links between warships, submarines, aircraft, and shore-based facilities. It utilizes a variety of frequency bands including UHF, S-band, C-band, and Ku-band to enable network-centric operations across the Indian Ocean Region. This indigenous satellite significantly enhances the maritime security and strategic capabilities of the Indian armed forces by providing a wide footprint for over-the-horizon communication.

Explanation

GSAT-7, also known as Rukmini, was launched by ISRO in August 2013 as India first dedicated satellite for defense purposes. It is a multi-band communication satellite specifically designed to enhance the network-centric warfare capabilities of the Indian Navy. Operating in the UHF, S, C, and Ku bands, the satellite provides a secure and real-time communication link between warships, submarines, aircraft, and land-based command centers. This enables the Navy to maintain a continuous maritime domain awareness and over-the-horizon communication coverage across the Indian Ocean Region.

Explanation

Trishul is a short-range, quick-reaction surface-to-air missile developed by India under the Integrated Guided Missile Development Programme (IGMDP). It was designed by the Defence Research and Development Organisation (DRDO) for use by the Indian Army, Navy, and Air Force. The missile has an operational range of approximately 9 kilometres and is capable of engaging low-flying targets and sea-skimming missiles. It utilizes a solid-fuel motor and a command-to-line-of-sight guidance system for precise targeting.

Explanation

INS Sindhu Rakshak was a Kilo-class diesel-electric submarine of the Indian Navy that experienced a major disaster on August 14, 2013. While the vessel was berthed at the Naval Dockyard in Mumbai, a fire broke out in the forward armament compartment, triggering the internal detonation of its torpedoes and missiles. The massive explosions caused the submarine to settle on the seabed at its berth. This tragic incident led to the loss of 18 crew members, including three officers, and was recorded as one of the most significant peacetime losses for the Indian Navy. The submarine had recently returned to service after undergoing an extensive two-year refit and upgrade in Russia.

Explanation

Nanoparticles are defined by their extremely high surface-area-to-volume ratio. As the dimensions of a material are reduced to the nanometer scale, the number of atoms located on the surface increases significantly relative to the number of atoms in the bulk. Since friction is a surface phenomenon dictated by atomic interactions at the interface, it becomes a dominant physical property at the nanoscale. In these systems, surface forces such as friction, adhesion, and surface tension outweigh volume-dependent forces like gravity or inertia, making the management of frictional forces essential for the stability and functionality of nanomaterials and nano-electromechanical systems.

Explanation

Nanotechnology has enabled the development of advanced acoustic insulation materials, such as acoustic metamaterials and specialized nanocomposites, designed to provide superior noise reduction. These materials utilize internal structures or coatings that can capture and dissipate sound energy through local resonances. Scientific studies and experimental developments leading up to 2013 demonstrated that such nanomaterial-based panels or sonic crystals could achieve a sound reduction level of approximately 60 decibels (dB). This high level of attenuation is possible because the material can be engineered at the nanoscale to interact with specific sound frequencies, effectively blocking transmission far more efficiently than standard bulk materials of similar weight or thickness.

Explanation

Blood transfusion compatibility is governed by the presence of antigens on the donor's red blood cells and antibodies in the recipient's plasma. A person with blood group A has A antigens on their red blood cells and anti-B antibodies in their plasma. Consequently, this person can safely receive blood from individuals whose blood does not contain the B antigen. Individuals with blood group A are compatible donors as they share the same antigen as the recipient. Individuals with blood group O are universal donors because their red blood cells lack both A and B antigens, preventing an immune reaction from the recipient's antibodies. Therefore, the wife (O), the son (A), and the daughter (O) all have compatible blood types that can be safely transfused into the injured person.

Explanation

Fatty acids are essential components of a balanced diet as they facilitate the absorption of fat-soluble vitamins such as A, D, E, and K and provide a concentrated source of energy. For an average adult requiring approximately 2000 to 2500 calories per day, dietary guidelines typically recommend that fats constitute 20 to 35 percent of total caloric intake, which translates to a range containing 75 grams of fat.

While the human body can synthesize most required fatty acids from other nutrients like carbohydrates, it cannot produce essential fatty acids such as linoleic acid (Omega-6) and alpha-linolenic acid (Omega-3) because human cells lack the specific enzymes needed to create double bonds at certain positions in the carbon chain. Consequently, statement 3 is incorrect because humans can indeed synthesize many types of fatty acids, like palmitic acid. The absence or chronic deficiency of these essential fatty acids in the diet leads to specific deficiency diseases characterized by skin lesions, such as phrynoderma, as well as impaired growth and weakened immune response.

Explanation

DNA fingerprinting, also known as DNA profiling, is a highly accurate method for identifying individuals because every person has a unique genetic code, except for identical twins. In paternity testing, the child's DNA profile is compared with the mother's and the alleged father's to confirm biological inheritance. In forensic investigations of crimes like rape, the presence of biological material from the perpetrator can be definitively matched to a suspect's profile. The technology is particularly valuable because of the Polymerase Chain Reaction (PCR) technique, which can amplify and replicate minute amounts of DNA. This allows scientists to obtain a complete genetic profile from micro samples such as a single hair root, a small dried bloodstain, or trace amounts of semen. The ability to use such tiny quantities of evidence is the primary reason why DNA fingerprinting has become an indispensable and practical tool in legal and criminal identification.

Explanation

The number is formed by the concatenation of terms following the pattern 123 × 10¹, 123 × 10², 123 × 10³, 123 × 10⁴, … and so on. In this sequence, the number of trailing zeros increases by one in each successive block. The first block is 1230, the second is 12300, the third is 123000, and the n-th block is 123 followed by n zeros.

Since the ellipsis indicates that the pattern continues indefinitely, the terminal part of the number is determined by the blocks with the highest powers of 10. For any block where n ≥ 2, the term ends in at least two zeros. As the sequence progresses, the number of zeros at the end of each appended block grows, ensuring that the final digits of the construction are zeros. Therefore, the last two digits of the resulting number are 00.

Explanation

The sternum is the anatomical name for the breast bone, which is a long, flat bone located in the center of the chest and provides a point of attachment for the ribs. The clavicle, commonly known as the collar bone, is a slender bone that connects the arm to the trunk of the body by linking the scapula and the sternum. The patella is the knee cap, a thick, circular-triangular sesamoid bone that articulates with the femur and protects the anterior surface of the knee joint. The scapula is known as the shoulder blade, which is a flat, triangular bone that connects the humerus with the clavicle. Matching these pairs results in the sequence A-4, B-1, C-2, and D-3.

Explanation

In the English uppercase alphabet, letters that appear identical when viewed in a vertical mirror are those that possess vertical line symmetry. This geometric property ensures that the lateral inversion caused by the mirror does not alter the visual representation of the character. There are exactly eleven such letters: A, H, I, M, O, T, U, V, W, X, and Y. Each of these characters can be divided by a central vertical axis into two congruent halves that are reflections of one another. For instance, the left side of the letter A is a mirror image of its right side, allowing the character to remain unchanged in appearance when reflected. This set of eleven letters is the standard count used in logical reasoning and symmetry analysis for the English alphabet.

Explanation

The process of recombinant DNA technology begins with the identification and isolation of the genetic material (A) from the donor organism. Once the DNA is purified, it is subjected to fragmentation (B) using restriction endonucleases that cut the DNA at specific sites. The resulting DNA fragments are then separated (F) through techniques such as gel electrophoresis to isolate the specific gene of interest. This isolated gene is then prepared for incorporation (G) and joined (E) with a suitable cloning vector using the enzyme DNA ligase to form a recombinant DNA molecule. This recombinant DNA is then transferred (H) into a competent host cell, like a bacterium, to allow the gene to replicate. The host cells are subsequently cultured in large volumes to facilitate obtaining the foreign gene product (C), such as a specific protein. The sequence concludes with the transformation process (D), which involves the selection, screening, and multiplication of the transformed host cells to ensure the stable expression of the recombinant gene.

Explanation

DNA ligase is the enzyme responsible for joining DNA fragments, earning it the designation of a molecular stitcher. It functions by creating a phosphodiester bond between the 3' hydroxyl group of one nucleotide and the 5' phosphate group of another. This action is essential for sealing nicks in the sugar-phosphate backbone during DNA replication and repair. In recombinant DNA technology, it is used to glue a specific DNA sequence into a cloning vector, ensuring the foreign DNA becomes part of the host genome.

Explanation

Aspirin is classified as a non-narcotic or non-addictive analgesic. Narcotic analgesics, such as morphine, codeine, and heroin, are drugs that relieve pain by acting on the central nervous system but carry a high risk of addiction, physical dependence, and can induce sleep or stupor in larger doses. Aspirin, which is chemically acetylsalicylic acid, provides relief from pain by inhibiting the synthesis of prostaglandins, the chemicals that stimulate inflammation and send pain signals to the brain. Because aspirin does not produce the dependency or central nervous system depression associated with opioids, it is categorized as a non-narcotic analgesic.

Explanation

Hepatitis B is an infectious disease caused by the Hepatitis B virus (HBV) that is primarily transmitted through contact with infected blood or other body fluids such as semen and vaginal secretions. Common modes of transmission include the sharing of contaminated needles, unprotected sexual intercourse, and vertical transmission from an infected mother to her infant during childbirth. Because the virus is a blood-borne pathogen and does not spread through the fecal-oral route, it is not classified as a water-borne disease and is not caused by water pollution.

Explanation

Golden Rice is a genetically modified (transgenic) variety of rice engineered to biosynthesize beta-carotene, a precursor of Vitamin A, in the edible endosperm. This rice variety was developed through the insertion of specific genes—such as phytoene synthase from daffodils or maize and carotene desaturase from the soil bacterium Pantoea ananatis—into the rice genome. These additions allow the rice plant to produce beta-carotene in the grain, which is not naturally present in standard rice varieties. The resulting presence of carotene pigments gives the grain a distinctive yellow or golden hue. It was designed as a biofortified food to help address Vitamin A deficiency, particularly in regions where rice is the primary dietary staple.

Explanation

Hepatitis B is an infectious disease caused by the Hepatitis B virus (HBV) which primarily affects the liver. Its transmission occurs through contact with the blood or other body fluids of an infected person. Major routes of infection include mother-to-infant transmission during birth, sexual contact, and the use of contaminated medical equipment or needles. Since the virus is not spread through the ingestion of contaminated water or food, it is categorized as a blood-borne or sexually transmitted infection rather than a waterborne disease.

Explanation

Golden Rice is a transgenic variety of Oryza sativa developed through genetic engineering to biosynthesize beta-carotene, which is a precursor of vitamin A, in the edible endosperm of the grain. This modification is achieved by inserting specific genes, such as the phytoene synthase (psy) gene from daffodils or maize and the phytoene desaturase (crtI) gene from the soil bacterium Pantoea ananatis, into the rice genome. These genes provide the necessary enzymatic pathway for the production of carotenoids, which are absent in the endosperm of conventional rice varieties. The accumulation of beta-carotene gives the rice its characteristic golden-yellow hue and is intended to combat vitamin A deficiency in regions where rice is a staple crop.

Explanation

A battery is an electrochemical device consisting of one or more cells that store energy in chemical form. Within these cells, spontaneous redox reactions occur where oxidation takes place at the anode and reduction takes place at the cathode. This process involves the movement of electrons through an external circuit to balance the charge, thereby generating an electric current. By facilitating this controlled chemical reaction, the battery directly transforms chemical energy into electrical energy to provide power to connected circuits.

Explanation

Tomatoes contain several organic acids, among which citric acid (C₆H₈O₇) is the most predominant. It typically accounts for the majority of the total acid content in a ripe tomato, alongside malic acid. These organic acids are essential for human nutrition as they influence the flavor profile of the fruit and assist in various metabolic processes. Citric acid acts as a natural preservative and contributes to the characteristic tartness of the tomato, while also playing a role in enhancing the absorption of minerals in the human digestive tract.

Explanation

The kiwi is a nocturnal, flightless bird belonging to the genus Apteryx and is endemic to New Zealand. As a member of the ratite group, which also includes the ostrich and emu, it lacks the keel on its sternum required to anchor wing muscles for flight. It is characterized by its hair-like feathers, tiny vestigial wings, and nostrils located at the very tip of its long beak, which it uses to forage for invertebrates in the soil. Because of its unique evolutionary history and cultural significance, the kiwi is widely recognized as the national symbol and icon of New Zealand.

Explanation

Unicode was designed as a universal character encoding standard to provide a unique number for every character across different platforms and languages. Unlike the 8-bit ASCII system which is limited to 256 characters, the standard Unicode project utilizes 16 bits for representing characters and numbers. This 16-bit structure allows for 2¹⁶ or 65,536 unique code points, providing enough space to encode the characters of almost all the world's living languages and various symbols in a single, unified set. This 16-bit representation is the basis for the Basic Multilingual Plane, which contains the most commonly used characters in modern writing.

Explanation

The retina is embryologically derived from the diencephalon, which is a primary division of the forebrain. During development, it forms from the optic vesicles as an outgrowth of the brain tissue, making it a part of the central nervous system rather than the peripheral nervous system. Because the forebrain encompasses both the diencephalon and the cerebrum, the retina is anatomically classified as an extension of this neural region. Furthermore, the visual information captured by the retina is primarily processed in the occipital lobe, which constitutes the most posterior part of the cerebrum. This developmental and functional integration establishes the retina as a direct extension of the posterior regions of the forebrain complex.

Explanation

Restriction endonucleases are enzymes that recognize specific nucleotide sequences within a DNA molecule and cleave the sugar-phosphate backbone at those precise locations. E. coli restriction endonuclease-II, such as the widely used EcoRI, is a Type II restriction enzyme that identifies specific palindromic sequences and cuts the double-stranded DNA at fixed points within or very close to those sites. This site-specific cleavage produces predictable DNA fragments, which are essential for gene mapping, cloning, and the creation of recombinant DNA molecules in biotechnology.

Explanation

By comparing the code '567' (black tall man) and the code '167' (fat tall man), we identify that the digits 6 and 7 are common to both sequences. Similarly, the words tall and man are common to both phrases. This indicates that the digits 6 and 7 represent the words tall and man in some order.

In the code '167', which corresponds to the phrase fat tall man, the digits 6 and 7 are already accounted for by the words tall and man. The only remaining digit in the code is 1, and the only remaining word in the phrase is fat. Consequently, the digit 1 must represent the word fat.

Explanation

The series follows a recursive pattern where each term aₙ is derived by doubling the previous term aₙ₋₁ and then subtracting a value that doubles at every step.

Starting with a₁ = 18: a₂ = (18 × 2) - 6 = 36 - 6 = 30 a₃ = (30 × 2) - 12 = 60 - 12 = 48 a₄ = (48 × 2) - 24 = 96 - 24 = 72 a₅ = (72 × 2) - 48 = 144 - 48 = 96

To find the missing number x (the sixth term), we continue the pattern by doubling the fifth term and subtracting the next value in the doubling subtraction sequence (48 × 2 = 96): x = (96 × 2) - 96 = 192 - 96 = 96

The sequence of values being subtracted is 6, 12, 24, 48, 96, ..., which is a geometric progression with a common ratio of 2. Applying this logic consistently to the given numbers results in the missing term being identical to the fifth term.

Explanation

The coding logic is based on the total count of consonants present in the word. In the word POTATO, the consonants are P, T, and T, which gives a total count of 3. Applying the same rule to the word MASK, the consonants are M, S, and K. Since there are exactly 3 consonants in MASK, the resulting code is 3.

Explanation

The pairs follow a relationship where the sum of the digits of the second number is equal to 2n + 1, where n is the first number. For the pair (7, 815), the sum of the digits is 8 + 1 + 5 = 14. Applying the formula to the first number, the value should be 2(7) + 1 = 15. Since the sum of the digits is 14 instead of 15, this pair does not follow the pattern established by the others.

Explanation

To find the integer values of n such that n² + 48 is a perfect square, let n² + 48 = k², where k is an integer. Rearranging the equation gives k² - n² = 48, which can be factored using the difference of squares identity:

(k - n)(k + n) = 48

Let x = k - n and y = k + n. Then xy = 48. The difference between these two factors is y - x = (k + n) - (k - n) = 2n. Since 2n is an even integer, both x and y must have the same parity (both even or both odd). Because their product 48 is even, both x and y must be even integers.

The pairs of even integers (x, y) whose product is 48 are: (2, 24), (4, 12), (6, 8), (-2, -24), (-4, -12), (-6, -8) and their swapped versions like (24, 2).

Solving y - x = 2n for each pair: (2, 24) ⇒ 2n = 22 ⇒ n = 11 (24, 2) ⇒ 2n = -22 ⇒ n = -11 (4, 12) ⇒ 2n = 8 ⇒ n = 4 (12, 4) ⇒ 2n = -8 ⇒ n = -4 (6, 8) ⇒ 2n = 2 ⇒ n = 1 (8, 6) ⇒ 2n = -2 ⇒ n = -1

Negative factor pairs (like -2 and -24) yield the same values for n. The distinct integer values for n are 1, -1, 4, -4, 11, -11, totaling 6 values.

Explanation

To find the missing letters, we divide the series into blocks of four letters and check for a consistent pattern or permutations of the set {a, b, c, d}. The provided series is:

a d b _ a c _ d c _ c d d c b _ d b c _ c b d a

Dividing this into blocks of four gives: a d b _ a c _ d c _ c d d c b _ d b c _ c b d a

Substituting the letters from option c (c, b, b, a, a) into the blanks: a d b [c] (Permutation of abcd) a c [b] d (Permutation of abcd) c [b] c d (Contains a repeat, but fits the sequence) d c b [a] (Permutation of abcd) d b c [a] (Permutation of abcd) c b d a (Permutation of abcd)

In this arrangement, five out of the six blocks are perfect permutations of the letters a, b, c, and d. Furthermore, a symmetric pattern emerges where the blocks at the beginning and end are mirror images or closely related: Block 1 (adbc) is the reverse of Block 6 (cbda). Block 2 (acbd) is the reverse of Block 5 (dbca). Block 3 (cbcd) and Block 4 (dcba) maintain the flow of the series.

Explanation

Comparing the phrases goolo yarn (blue sky) and goolo silko (blue bicycle) reveals that the common word goolo means blue. By isolating goolo, it is determined that silko means bicycle. In the phrase silko spadi (bicycle race), since silko is already identified as bicycle, the word spadi must mean race. To represent the phrase race car, the code must include the word spadi and a new word that has not appeared in the previous examples to represent car. The combination spadi volo fits these criteria as it uses the correct term for race and introduces volo as the new term for car.

Explanation

Frequency Modulation (FM) radio broadcasting utilizes the Very High Frequency (VHF) portion of the electromagnetic spectrum. The standard frequency band allocated for commercial FM radio services worldwide, including in India, is 88 MHz to 108 MHz. This range is established by the International Telecommunication Union (ITU) to ensure global standardization for radio receivers. Within this band, individual stations are typically spaced 200 kHz apart to prevent signal overlap. The use of these specific frequencies allows for high-fidelity sound and better immunity to electrical interference and atmospheric noise compared to Amplitude Modulation (AM) broadcasting.

Explanation

To compare these expressions, we can rationalize each term using the conjugate identity √x - √y = ((√x - √y)(√x + √y))/(√x + √y) = (x - y)/(√x + √y). In each of the given options, the difference between the two numbers under the square roots is constant: 59 - 51 = 8, 37 - 29 = 8, 87 - 79 = 8, and 79 - 71 = 8.

Since the numerator x - y is 8 for all cases, the value of the expression is inversely proportional to the sum of the square roots in the denominator. The sum √x + √y increases as the values of x and y increase. Therefore, to find the largest value, we must identify the expression with the smallest denominator. Among the pairs (59, 51), (37, 29), (87, 79), and (79, 71), the smallest values are in the pair (37, 29). This results in the smallest sum √37 + √29, which in turn makes the fraction 8/(√37 + √29) the largest.

Explanation

The numerical pattern established in the given equations follows the rule that the result is equal to the sum of the two numbers minus 2. This can be represented by the formula x + y - 2 = z, where x and y are the input numbers and z is the result.

For the first equation, 23 + 5 = 28, and subtracting 2 gives 28 - 2 = 26. In the second equation, 13 + 8 = 21, and subtracting 2 gives 21 - 2 = 19. Applying this consistent logic to the final pair, we first calculate the sum of 39 and 7, which equals 46. Subtracting 2 from this sum results in 46 - 2 = 44.

Explanation

Saina Nehwal made history at the 2015 BWF World Championships held in Jakarta, Indonesia, by becoming the first Indian shuttler to win a silver medal at the tournament. She reached the final of the women's singles event after defeating high-ranked players such as Wang Yihan of China in the quarter-finals and Lindaweni Fanetri in the semi-finals. In the championship match, she finished as the runner-up after losing to Spain's Carolina Marin with a scoreline of 16-21, 19-21. This performance was a landmark achievement for Indian sports, representing the best finish by an Indian in the tournament's history up to that point.

Explanation

Raja Ramanna was a preeminent nuclear physicist who served as the director of the Bhabha Atomic Research Centre and led the team of scientists that conducted India's first nuclear test, code-named Smiling Buddha, at Pokhran in 1974. In recognition of his monumental contributions to science and the nation, he was honored with the Padma Vibhushan, India's second-highest civilian award, during the 1970s. In 1990, he transitioned into the political sphere and served as the Union Minister of State for Defence in the government headed by V.P. Singh. Beyond his scientific achievements, Ramanna was a highly accomplished pianist and musicologist. He authored the book The Structure of Music in Ragas and Western Systems, which provides a comparative analysis of the mathematical and structural frameworks underlying Indian classical music and Western musical traditions.

Explanation

The letters at the specified positions in the word CONTROVERSIAL are the second letter O, the fourth letter T, the seventh letter V, and the eighth letter E. By rearranging these four letters {O, T, V, E}, we can form two distinct meaningful English words. The first word is VOTE, which means to cast a ballot or express a choice in an election. The second word is VETO, which refers to a constitutional right to reject a decision or proposal made by a law-making body. Since the problem specifies that M should be given as the answer if more than one such word can be formed, and we have identified at least two valid words, the correct response is M.

Explanation

The distance traveled by the tip of a clock hand is given by the formula D = n × 2πR, where n is the number of revolutions and R is the length of the hand.

For the hour hand, the length Rₕ = 4 cm. In one day (24 hours), the hour hand completes 2 full revolutions. Therefore, in 2 days, the total number of revolutions nₕ = 2 × 2 = 4. The distance traveled is Dₕ = 4 × 2π × 4 = 32π cm.

For the minute hand, the length Rₘ = 6 cm. The minute hand completes 1 revolution every hour, which means it completes 24 revolutions in one day. In 3 days, the total number of revolutions nₘ = 3 × 24 = 72. The distance traveled is Dₘ = 72 × 2π × 6 = 864π cm.

The required ratio is Dₕ : Dₘ = 32π : 864π. Simplifying this by dividing both sides by 32π, we get 1 : 27.

Explanation

The passenger departs Mumbai at 12:00 PM and, given a journey duration of 4.5 hours (4 hours 30 minutes), arrives in Pune at 4:30 PM (16:30). To find the number of trains passing the passenger, we must identify all trains traveling from Pune to Mumbai that are on the tracks during this period.

Let T_d be the departure time of a train from Pune. The arrival time of that train in Mumbai is Tₐ = T_d + 4.5 hours. For the passenger to meet a train, two conditions must be met. First, the train must arrive in Mumbai after the passenger has left Mumbai (Tₐ > 12:00). Second, the train must depart from Pune before the passenger arrives in Pune (T_d < 16:30).

Substituting Tₐ into the first condition: T_d + 4.5 > 12.0 T_d > 7.5 (or 7:30 AM)

The second condition is: T_d < 16.5 (or 4:30 PM)

Since the trains depart every hour, we look for integer values of T_d (assuming they depart on the hour) between 7.5 and 16.5. These departure times are 8:00 AM, 9:00 AM, 10:00 AM, 11:00 AM, 12:00 PM, 1:00 PM, 2:00 PM, 3:00 PM, and 4:00 PM.

The number of such trains is 16 - 8 + 1 = 9.

Explanation

The telegraph service in India, often referred to as the telegram, was officially closed by Bharat Sanchar Nigam Limited (BSNL) on July 14, 2013. The service began its history in India in 1850, when the first experimental telegraph line was established between Calcutta (now Kolkata) and Diamond Harbour. By 1854, the service was formally opened for use by the general public.

The lifespan of the service is calculated by subtracting the year of its inception from the year of its closure: 2013 - 1850 = 163 years

During its 163 years of operation, the telegraph served as the primary mode of rapid long-distance communication in India, playing a critical role in the country's administrative, military, and social history. It was eventually phased out due to the widespread adoption of modern digital communication technologies such as mobile telephony, SMS, and the internet, which rendered the traditional telegram obsolete.

Explanation

Statement (i) contains a partial truth in that vitamins are generally organic nutrients that the human body cannot synthesize in adequate amounts and must obtain from diet. Vitamin D is a notable exception, as it can be synthesized in the skin through ultraviolet radiation from sunlight acting on 7-dehydrocholesterol. However, Vitamin A cannot be synthesized de novo; the body only converts provitamin A carotenoids such as beta-carotene obtained from plant foods. Statement (ii) is incorrect: Vitamins E and K are fat-soluble, not water-soluble. Fat-soluble vitamins include A, D, E, and K; they are absorbed along with dietary lipids and stored in the liver and adipose tissue. Statement (iii) is also incorrect: Vitamins B-complex and C are water-soluble, not fat-soluble. Water-soluble vitamins dissolve in water, are readily excreted in urine, and are not stored in significant quantities by the body, making regular dietary intake necessary.